Arm chair



FIG. 1 is a front perspective view showing the new design;

FIG. 2 is a front view thereof;

FIG. 3 is a back view thereof;

FIG. 4 is a left side view thereof,

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines shown are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for an arm chair, as shown and described. 